• Proceedings of the Korean Nuclear Society Conference
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• 1996.05c
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• pp.403-408
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• 1996

석탄화력발전소 폐기물인 석탄회와 요오드화 세슘의 반응특성을 DTA(Differential Thermal Analysis), TGA(Thermo-Gravimetric Analysis) 장치를 이용하여 분석하였다. 본연구에 사용된 석탄회는 85%의 실리카와 알루미나를 함유하고 있으며 Si/Al 몰비는 2.1 이었다. DTA와 TGA의 열분석 결과 CsI의 분해, 석탄회와 기체상 세슘의 반응 등으로 이루어져 있다. 석탄회와 CsI의 혼합물은 94$0^{\circ}C$ 이상에서 Pollucite 가 형성되었다. 반응생성물들의 SEM 분석결과 표면이 거칠며 bulky한 crystal 형태로서 구형의 석탄회와는 매우 다른 형상을 보였다. 석탄회는 요오드화세슘의 고정화를 위해서 적합한 알루미노규산염 원료물질들 중의 하나임을 확인하였다.

• Journal of the Society of Disaster Information
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• v.19 no.3
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• pp.532-544
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• 2023

Purpose: To identify and evaluate the risk of chemical fire causative substances by using thermal analysis methods (DSC, TGA) for the hazards and physical property changes that occur when newly used biofuels are mixed with existing fuels It is to use it for identification and evaluation of the cause of fire by securing data related to the method and the hazards of the material according to it. Method: The research method used in this experiment is the differential scanning calorimeter (DSC: Difference in heat flux) through quantitative information on the caloric change from the location, shape, number, and area of peaks. flux) was measured, and the weight change caused by decomposition heat at a specific temperature was continuously measured by performing thermogravimetric analyzer (TGA: Thermo- gravimetric Analyzer). Result: First, in the heat flux graph, the boiling point of the material and the intrinsic characteristic value of the material or the energy required for decomposition can be checked. Second, as the content of biodiesel increased, many peaks were identified. Third, it was confirmed through analysis that substances with low expected boiling points were contained. Conclusion: It was shown that the physical risk of the material can be evaluated by using the risk of biodiesel, which is currently used as a new energy source, through various physical and chemical analysis techniques (DSC + TGA).In addition, it is expected that the comparison of differences between test methods and the accumulation and utilization of know-how on experiments in this study will be helpful in future studies on physical properties of hazardous materials and risk assessment of materials.

• Nuclear Engineering and Technology
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• v.49 no.4
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• pp.873-880
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• 2017

To identify the feasibility of disposing of spent activated carbon as a clearance level waste, we performed characterization of radioactive pollution for spent activated carbon through radioisotope analysis; results showed that the C-14 concentrations of about half of the spent activated carbon samples taken from Korean NPPs exceeded the clearance level limit. In this situation, we selected thermal treatment technology to remove C-14 and analyzed the moisture content and thermal characteristics. The results of the moisture content analysis showed that the moisture content of the spent activated carbon is in the range of 1.2-23.9 wt% depending on the operation and storage conditions. The results of TGA indicated that most of the spent activated carbon lost weight in 3 temperature ranges. Through py-GC/MS analysis based on the result of TGA, we found that activated carbon loses weight rapidly with moisture desorption reaching to $100^{\circ}C$ and desorbs various organic and inorganic carbon compounds reaching to $200^{\circ}C$. The result of pyrolysis analysis showed that the experiment of C-14 desorption using thermal treatment technology requires at least 3 steps of heat treatment, including a heat treatment at high temperature over $850^{\circ}C$, in order to reduce the C-14 concentration below the clearance level.

• Analytical Science and Technology
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• v.24 no.3
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• pp.168-172
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• 2011

The iron frame of building could be collapsed or bent at $500^{\circ}C$. Therefore the fire-resistant paint should be applied for safety. This study performed the comparative analysis to show the characteristics of fireresistant paint. And then 12 products of fire resistant paint and 6 products of paints were used as samples. And the samples were analyzed by TGA (Thermogravimetric Analyzer) as analyzer for measuring the variation of weight on temper of weight by heating. When TGA analyzer could measure the variatiature, and FT-IR was measured for analyze gas components on variation on of weight by heating on 12 products of fire resistance, the samples showed to decrease 40% of weight to $800^{\circ}C$, and because paints had 50% to 40% of loss weight, it showed to be equal with loss weight of fire resistance paint on high temperature or was lower loss weight than it of fire resistance paints. However number 6 sample of fire resistance paints could show to decrease 20% of total weight on $800^{\circ}C$. And then in the case of FT-IR, fire resistance paints could show to have the high intensity of $CO_2$ spectrum as complete combustion. However paints could show to have the lower intensity of $CO_2$ spectrum, have the higher intensity of water spectrum. Therefore the TGA graph of result could be much different until $250^{\circ}C$. When it was burned, FT-IR spectrum could show to confirm the characteristics of fire resistance paints, and the characteristic could be confirmed on inorganic paint of fire resistance by weight loss of TGA.

• Korean Chemical Engineering Research
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• v.48 no.1
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• pp.110-115
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• 2010

The experiment was designed to compare pyrolysis kinetics of two different classes of imported coal. The pyrolysis behaviors of the coals were first observed with thermogravimetric analyzer(TGA). The kinetic analysis was further done based on a new distributed activation energy model(New DAEM). During the analysis, weight loss curves measured at three different heating rates were used to obtain the activation energy distribution function curve f(E) of a given coal sample where a mean activation energy is determined by its peak. The results show a significant difference in the mean activation energy between two coals for the pyrolytic reaction. The prediction of a chemical percolation devolatilization(CPD) model where the kinetics obtained from the New DAEM method were incorporated is in much closer agreement with an experimental data of TGA particularly for the bituminous coal.

• Journal of the Korean Wood Science and Technology
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• v.33 no.4 s.132
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• pp.38-44
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• 2005

This study was carried out to investigate the combustion characteristics of flame retardant treated wood by water-soluble flame retardants which are made from mixture of aqueous solution of monoammonium phosphate, sodium borate and zinc borate. The combustion characteristics for flame retardant treated wood were carried out using thermal analysis (TGA, combustion heat) and flame retardant test (LOI, flame propagation). The results of thermal analysis and flame retardant test are as follows; 1) The sample treated by F4 showed excellent flame retardant effects in almost all of combustion characteristics. 2) From TGA curves, all the samples undergo pyrolysis and oxidation in two main discrete steps. 3) The effect of flame retardant for softwood is higher than those for hardwood, and the combustion heat has decreased with increase of the content of flame retardant. 4) LOI values are almost similar in flame retardant treated wood samples. The range of LOI is from 24 to 30. However, these values are much higher than LOI value of non-treated wood sample. 5) The blended aqueous solution had a final in the range of about pH 8.4, and a slight odor of ammonia.

• Elastomers and Composites
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• v.42 no.1
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• pp.55-58
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• 2007

Thermal Characterization of an EPDM/IIR rubber blend was performed using TG/DTG analysis. While TGA thermograms of a virgin EPDM and IIR showed their own characteristic thermal decomposition curves, that of an EPDM/IIR blend sample showed a characteristic curve, exhibiting both decomposition characteristics of EPDM and IIR. This finding was more clarified from DTG analysis obtained by differentiation of TGA thermograms, being exhibited as two distinct shifted-peaks. Degrees of peak-shift (${\Delta}T$) compared to their original positions were $+25\;^{\circ}C$ for IIR and $-15\;^{\circ}C$ for EPDM, respectively. From these facts, thermal stability of EPDM is considered comparatively better than IIR, and moreover, it can be an evidence for the characteristics of a partial compatibility between EPDM and IIR. It is noteworthy that, if we prepare in advance a calibration curve for the composition about EPDM/IIR blend, it may be possible to analyze quantitatively an EPDM/IIR blend, using comparatively simple TGA experiments as in the present work.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.2
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• pp.104-110
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• 2019

The thermal decomposition characteristics of boron-potassium nitrate ($BKNO_3$) were investigated by non-isothermal thermal gravimetric analysis (TGA). Two steps of mass loss were observed in the temperature range between room temperature and $600^{\circ}C$. Kinetic parameters of the thermal decompositions were evaluated from the measured TGA curves using the AKTS Thermokinetics Software. For the first step of mass loss ($220-360^{\circ}C$) corresponding to the thermal decomposition process of the binder (Laminac/Lupersol), the activation energy is in the range of approximately 120-270 kJ/mol when evaluated by Friedman's iso-conversional method, while the value of activation energy varies in the range of approximately 150-400 kJ/mol during the second step process ($360-550^{\circ}C$).

• New & Renewable Energy
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• v.16 no.2
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• pp.47-53
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• 2020

The amount of food waste and its water content depends on both the season and region. In particular, the water content typically varies between 73.8 wt.% and 83.3 wt.%, depending on the proportion of vegetables. Current food waste drying technologies are capable of reducing the water content to less than 10 wt.%, while increasing the heating value. Ongoing studies aim to utilize dried food waste as fuel. Food waste can be used to produce solid refuse fuel (SRF) by mixing it with various solid fuels or other types of waste. The analysis of specimens is very important when considering the direct combustion of food waste or its co-firing with solid fuels. In this study, the weight reduction of specimens after burning them in a small combustor, and compared with the results of thermogravimetric analysis (TGA). The concentration of various chemicals was also measured to define the characteristics of waste generation. Performed proximate analysis, elemental analysis, TGA, combustion experiment, the heating value, and derivative thermogravimetry (DTG).

• Polymer(Korea)
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• v.28 no.6
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• pp.519-523
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• 2004

Starch was grafted with maleic anhydride by melt process and then the grafted starch was blended with poly(lactic acid). The thermal properties of the poly(lactic acid), poly(lactic acid)/starch, and poly(lactic acid)/ modified starch were observed by DSC and TGA analysis. In the case of poly(lactic acid)/modified starch, an additional melting peak at 1$65^{\circ}C$ accompanying with 172$^{\circ}C$ assigned to pure poly(lactic acid) melting transition was clearly displayed in DSC analysis. Also, smooth decomposition pattern between starch and poly(lactic acid) was also monitored in poly(lactic acid)/modified starch blend by TGA analysis. The modulus of poly(lactic acid)/modified starch was 12％ higher than that of poly(lactic acid)/starch. The thermal and mechanical characteristics of poly(lactic acid)/modified starch might be due to the enhanced compatibilization between each components, which was also observed in SEM analysis.